//
//  LoginView.swift
//  medmap
//

import SwiftUI

struct LoginView: View {

    @StateObject private var viewModel = LoginViewModel()
    @FocusState private var focusedField: Field?

    private enum Field {
        case email
        case password
    }

    var body: some View {
        ZStack {
            Color.appBackground.ignoresSafeArea()
            
            
            formPanel
            
                
           
        }
        //.preferredColorScheme(.light)
    }

    private var brandPanel: some View {
        ZStack(alignment: .bottomLeading) {
            Color.appBackground.ignoresSafeArea()

            Image("splashImage")
                .resizable()
                .scaledToFit()
                .frame(maxWidth: 360)
                .padding(40)
                .accessibilityHidden(true)

            VStack(alignment: .leading, spacing: 10) {
                Image("splashLogo")
                    .resizable()
                    .scaledToFit()
                    .frame(width: 146, height: 96)
                    .accessibilityHidden(true)
                Text("MedMap")
                    .font(.jakartaBold24)
                    .foregroundStyle(.white)
                Text("Acompanhamento simples da sua medicacao.")
                    .font(.jakartaRegular16)
                    .foregroundStyle(.white.opacity(0.84))
                    .fixedSize(horizontal: false, vertical: true)
            }
            .padding(44)
        }
        .ignoresSafeArea()
    }

    private var formPanel: some View {
        VStack(spacing: 0) {

            Spacer(minLength: 32)

            VStack(alignment: .leading, spacing: 24) {
                VStack(alignment: .leading, spacing: 10) {
                    if UIDevice.current.userInterfaceIdiom == .phone {
                        Image("splashLogo")
                            .resizable()
                            .scaledToFit()
                            .frame(width: 120, height: 76)
                            .accessibilityHidden(true)
                    }

                    Text("Aceda aqui à sua conta")
                        .font(.jakartaBold24)
                        .foregroundStyle(.white)
                }

                VStack(spacing: 14) {
                    loginField(
                        placeholder: "Email",
                        icon: "envelope",
                        text: $viewModel.email,
                        field: .email,
                        contentType: .emailAddress,
                        keyboardType: .emailAddress
                    )

                    passwordField
                }

                if let errorMessage = viewModel.errorMessage {
                    Text(errorMessage)
                        .font(.jakartaRegular14)
                        .foregroundStyle(Color.loginErrorText)
                        .frame(maxWidth: .infinity)
                        .multilineTextAlignment(.center)
                        .fixedSize(horizontal: false, vertical: true)
                        .accessibilityLabel("Erro de autenticacao: \(errorMessage)")
                }

                Button {
                    focusedField = nil
                    Task {
                        await viewModel.login()
                    }
                } label: {
                    Group {
                        if viewModel.isLoading {
                            ProgressView()
                                .tint(Color.loginButtonText)
                        } else {
                            Text("Entrar")
                                .font(.jakartaBold16)
                        }
                    }
                    .frame(maxWidth: .infinity)
                    .frame(height: 46)
                }
                .foregroundStyle(Color.loginButtonText)
                .background(Color.loginButtonBackground)
                .clipShape(RoundedRectangle(cornerRadius: 8))
                .disabled(!viewModel.canSubmit)
                .opacity(viewModel.canSubmit ? 1 : 0.55)
                .accessibilityHint("Inicia sessao na conta de doente")

                Text("Não tem conta? Criar conta")
                    .font(.jakartaRegular14)
                    .foregroundStyle(.white.opacity(0.88))
                    .frame(maxWidth: .infinity)
                    .multilineTextAlignment(.center)
            }
            .padding(.horizontal, 32)

            Spacer()

            Text("MedMap")
                .font(.jakartaRegular12)
                .foregroundStyle(.white.opacity(0.6))
                .padding(.bottom, 24)
        }
    }

    private var passwordField: some View {
        loginFieldContainer(icon: "lock") {
            ZStack(alignment: .leading) {
                if viewModel.password.isEmpty {
                    Text("Palavra-passe")
                        .foregroundStyle(Color.loginPlaceholder)
                }
                SecureField("", text: $viewModel.password)
                    .foregroundStyle(.white)
                    .tint(.white)
                    .textContentType(.password)
                    .focused($focusedField, equals: .password)
                    .submitLabel(.go)
                    .onSubmit {
                        Task {
                            await viewModel.login()
                        }
                    }
            }
        }
        .accessibilityLabel("Palavra-passe")
    }

    private func loginField(
        placeholder: String,
        icon: String,
        text: Binding<String>,
        field: Field,
        contentType: UITextContentType,
        keyboardType: UIKeyboardType
    ) -> some View {
        loginFieldContainer(icon: icon) {
            ZStack(alignment: .leading) {
                if text.wrappedValue.isEmpty {
                    Text(placeholder)
                        .foregroundStyle(Color.loginPlaceholder)
                }
                TextField("", text: text)
                    .foregroundStyle(.white)
                    .tint(.white)
                    .textContentType(contentType)
                    .keyboardType(keyboardType)
                    .textInputAutocapitalization(.never)
                    .autocorrectionDisabled()
                    .focused($focusedField, equals: field)
                    .submitLabel(.next)
                    .onSubmit {
                        focusedField = .password
                    }
            }
        }
        .accessibilityLabel(placeholder)
    }

    private func loginFieldContainer<Content: View>(
        icon: String,
        @ViewBuilder content: () -> Content
    ) -> some View {
        HStack(spacing: 10) {
            Image(systemName: icon)
                .foregroundStyle(.white)
                .frame(width: 18)
            content()
                .font(.jakartaRegular16)
        }
        .padding(.horizontal, 14)
        .frame(height: 46)
        .background(Color.loginFieldBackground)
        .overlay {
            RoundedRectangle(cornerRadius: 8)
                .stroke(Color.loginFieldBorder, lineWidth: 1)
        }
        .clipShape(RoundedRectangle(cornerRadius: 8))
    }
}

#Preview {
    LoginView()
}